Deinking solution



Patented Sept. 10, 1929.

UNITED' STATES WILLIAM LEWIS, OF VANCOUVER, BRITISH COLUMBIA, CANADA.

DEINKING SOLUTION.

No Drawing. Application filed February 27, 1928, Serial No. 257,541, and in Canada December 12, 1927.

My invention relates to improvements in de-inking solutions, the objects of which are to provide means which will dissolve printers ink and the like on newspaper and other stock and so neutralize the fatty substances in the ink so as to enable it to be readily washed from the stock that the said stock may be re-used in the formation of paper or other paper products.

While many solutions have been compounded for this purpose, their use has entailed much labour and the solution and paper treated has to be subjected for extended periods of agitation at relatively high temperatures to the end that the process of reclaiming the de-inked pulp cost more than the value of the pulp. With the use of the solution hereinafter described, the paper, reduced to pulp form, is treated at ordinary water temperature and the ink removed therefrom with such celerity as to render the process very economical.

The solution is composed of certain ingredients which will obviously vary in quantity according to the paper stock to be de-inked and the components or quality of the ink used thereon. Generally on a common paper stock such as newsprint, a much weaker solution is required than for highly calendered papers.

For the de-inking of newsprint, I mix five parts of water glass consisting of sodium silicate, potassium silicate or both, with two parts of caustic soda or concentrated lye and one part of Pearline washing powder in about five thousand parts of water. The chemical composition of Pearline is as follows:

Per cent.

Moisture (H O) 44.90 Sodium carbonate (Na,oo,) 32.50 Soap powder (dry) 21.90 Sodium peroxide .70

containing waterglass alone, or without the addition of the other ingredients hereinbefore referred to.

The action of the solution upon the macerated stock liberates the ink, which being of lesser specific gravity than the solution floats readily to the surface and may be run 01f as it accumulates, if desired.

The paper so treated can be entirely freed of ink by successive immersions in this solution without heating and I have found that clean commercial pulp can be obtained from ordinary printed newsprint in from two to four minutes.

It will thus be seen that I have invented an extremely simple solution and method of deiuking printed paper, which is both economical and effective.

What I claim as my invention is:

1. The method of tie-inking printed paper stock whcih consists of saturating the paper in a solution of washing powder, lye, waterglass and water, and subsequently expressing the solution from the resulting pulp.

2. A de-inking solution consisting substantially of live parts of water glass, two parts of caustic soda. one part of Pearline and water in suitable proportion.

Dated at Vancouver, B. 0., this 17th day of February, 1928.

WILLIAM LEWIS. 

